The present invention relates to pumps in general, and more particularly to a high-pressure plunger pump.
There are already known various constructions of plunger pumps, among them such in which a pressure valve and a suction valve are coaxially arranged in a pump housing which includes a main body and a pump head secured to one end of the main body, a plunger extends into the interior of the pump housing, and a sleeve is floatingly supported on the plunger and has one end portion which is closer to the pump head than the other and converges toward the pump head, and in which the suction valve is constructed as a plate valve including a spring-loaded annular suction valve body which is supported at the region of its outer edge on an annular surface of an insert body which is secured in position in the pump head.
A high-pressure plunger pump of this kind is known, for instance, from the published German patent application DE-AS No. 26 31 217, in which the insert body is provided with a concentrically extending row of flow passages, the central longitudinal axis of which approximately corresponds to the angle of inclination of the converging portion of the sleeve. The structural embodiment of this known high-pressure plunger pump had, in principle, quite successfully proven its merits in practical applications. However, as a result of the arrangement and configuration of the flow passages in the insert body, there are obtained output-reducing flow resistances, which stand in the way of an optimum employment of the high-pressure plunger pump. The manufacture of the insert body which is provided with the flow passages creates difficulties which are not negligible. The insert body is subjected during the operation to alternating loads. For this reason, it is necessary to manufacture this insert body with a high precision and a high surface quality. Moreover, wear phenomena occur at the region of the pressure valve or of the suction valve, such phenomena also deleteriously influencing the cost-effectivenes of the high-pressure plunger pump.